The present invention relates to a method and an apparatus for processing water, and in particular to a method for processing water by adding chitin chitosan to electrolyzed water, which is obtained by electrolyzing water, and to an apparatus for such processing.
Chitin chitosan as used in this specification is defined as chitin or chitosan in isolated status or chitin and chitosan in mixed status, and water is defined as potable water, e.g. city water or well water.
Chitin is produced from limbs and shells of crabs, lobsters, shrimps, etc., and when it is used in drinks, it gives favorable influence to human body, for example, it suppresses aging, reinforces immunopotence, prevents or recovers various diseases, regulates autonomic nerves or maintains blood concentration at a constant level, or regulates hormone secretion. Or, when it is applied on skin, it is known that it provides astringent effect or rinse effect. Chitosan is a deacetylated product of chitin and has more powerful property than that of chitin, while, in the effects of the present invention, both substances have almost the same quality and the same property.
According to the manufacturing method of chitin chitosan as generally known, limbs and shells of crabs, lobsters, shrimps, etc. are dried and pulverized to granules. After removing protein, the granules are decalcified with hydrochloric acid or nitric acid, and the granular chitin is deacetylated by processing with caustic soda to prepare chitin chitosan, which contains chitosan by 50 to 90 weight % and chitin by 10 to 50 weight % in mixed state. It is difficult to deacetylate all of the chitin by the above processing with caustic soda, and chitin remains without being processed in the extent as described above.
The electrolyzed water is divided into cathodic water generated on cathode side and anodic water generated on anode side. The cathodic water is the so-called alkali ions water, and it tastes good when it is used for drinking or for cooking, while it is known that it gives favorable effects on human body, for example, it improves abnormal gastrointestinal fermentation, chronic diarrhea or hyperacidity and maintains stomach and intestines in good conditions, prevents cold and improves allergic constitution or various chronic diseases. On the other hand, anodic water has astringent effect (effect to contract skin) and rinse effect (effect to moisten skin) and effect to alleviate skin diseases when it is externally applied.
An electrolyzed water generator, i.e. a water processing apparatus for generating electrolyzed water, is divided into pool type and flowing type. In the pool type generator, water is pooled in an electrolytic cell and is electrolyzed for a given duration, and the electrolyzed water is then replaced with water, and the same procedure is repeated. This type of generator is disadvantageous in that much labor is required for replacement procedure. On the other hand, in the flowing type generator, water is passed through an electrolytic cell under city water pressure or pumping pressure and it is advantageous in that generated water can be obtained continuously, and it is used for general application.
In the flowing type electrolyzed water generator, free chlorine components contained in the water before electrolysis often remain on the cathode without being migrated toward the anode, and chlorine is mixed in the cathodic water used for drinking. In practical application, in order to produce and deliver more quantity of cathodic water than anodic water because it is consumed more than the anodic water, it is tried to give flow rate difference between cathode side and anode side separated via a diaphragm. For example, the electrolytic cell on the anode side is designed larger than that of the cathode side, or an orifice is provided on entrance and exit on anode side of the electrolytic cell to control the flow rate. As a result, pressure difference is generated between anode and cathode of the electrolytic cell, and chlorine condensed and separated at the anode leaks toward the cathode and chlorine may be mixed in the cathodic water.
Also, if the anodic water obtained in the above contains considerable amount of chlorine components, and if it is externally used without further processing, it may give detrimental effect on hypersensitive skin.
To prevent such negative effects, a dechlorination filter is arranged in a conventional type electrolyzed water generator as a pro-processing apparatus for the flowing type elecorolyzed water generator with the purpose of removing chlorine components contained in the water before it is electrolyzed. This dechlorination filter comprises granular or fibrous activated carbon for dechlorination effect as principal material. Further, calcium sulfite to reinforce dechlorination potency is added, or hollow yarn membranes are interwoven with the purpose of eliminating bacteria. Chlorine ions are adsorbed on activated carbon while free chlorine is not absorbed easily, and the above calcium sulfite converts the free chlorine to the chlorine ions, i.e. it has the property to increase dechlorination ability of the activated carbon.
However, in the dechlorination filter, adsorbing ability of activated carbon is often decreased by calcium sulfite, which is easily decomposed in water, iron rust, or bacterial products called slime, or hollow yarn membranes are clogged, thereby changing water flow rate. As a result, the balance between electric power for electrolysis and processed water quantity is changed, leading to the change in the quality of the generated water or to inability to provide the dechlorination. Because such change of water quality is not discernible from external appearance and can be identified only by reagent, there is the possibility that generated water having different quality from the originally intended quality may be used. In addition, the dechlorination filter is very expensive, and the replacement causes much burden on the users because the replacement procedure is complicated and difficult.
An idea has been proposed to arrange the filter only for the cathodic water of drinking purpose. In this case, however, water hardness components such as calcium, magnesium, etc. are condensed and contained in the cathodic water, and these components extremely reduces service life of the filter, on which the components are deposited and attached. Also, due to the change of hardness components in the cathodic water and filter clogging, flow rate balance between anodic water and cathodic water will be lost and water quality itself may be changed.